+########################################
+# clang-4
+clang-4-root: $CLANG4_ROOT/bin
+clang-4-cxx: clang++
+clang-4-cc: clang
+clang-4-cxxflags: -stdlib=libc++ -Wdocumentation
+clang-4-exe-ldflags: -L$CLANG4_ROOT/lib -Wl,-rpath=$CLANG4_ROOT/lib
+clang-4-extlib: rt
+clang-4-boost: $BOOST_ROOT
+clang-4-64-boost-lib: stage64-clang4/lib
+clang-4-64-asan-boost-lib: stage64-clang4-asan/lib
+clang-4-64-tsan-boost-lib: stage64-clang4-tsan/lib
+clang-4-gtest: $GTEST_ROOT
+clang-4-64-gtest-lib: $GTEST_ROOT/lib-clang4/libgtest.a
+